As regards the 4 extra APMs, I blame my high latency (80-100).
Yes, of course I have read odawgg's guide :P
One of the problems I have during my rotation is this: I have recently used HSM and RS (so they are on CD), due to bad luck none of my recent TMs has proc'd Barrage, but Unload is off CD. In such cases I do not put Unload in queue (during the cast of TM) because I do not want to use it un-Barrage'd and I do not put another TM in queue because if the current TM has proc'd Barrage I'd want to use Unload instead.
In order to see if a TM has proc'd Barrage I always wait for that whirling animation, but that appears AFTER the casting of TM has finished. As I understand Barrage procs at the START of the TM casting, right? If that means that the corresponding buff appears at the same time it would worth pumping up a bit the size of my buffs and focus on them in order to check if Barrage has proc'd. Maybe that would resolve my issue.
- - - Updated - - -
After a further analysis I see that I have 33 ability activations where I delayed more than 0.5'', 12 of which I delayed for more than 1'' (!!!) On the other hand I have 69 cases where my response is less than 0.1''
So I guess this is my main problem and there is room for improvement.